Porting Qt WebKit based project to Qt 5.7 (Qt WebEngine)

Hi, I am currently porting an existing program from Qt4 to Qt5.7.
I have used QWebPage in Qt4 and the porting guide said that I should use QWebEnginePage in Qt 5.7.
There are some methods for which I haven't found a replacement in Qt5 yet:
- QWebPage::setPreferredContentsSize()
- QWebFrame::setTextSizeMultiplier()
- QWebFrame::render()

For QWebFrame::render() I could probably use QWebEngineView::render(), or is there a way where I don't have to create a QWebEngineView Object?
What about the other two methods?

Ginsengelf